In order to provide exercise to muscle groups in the upper and lower body, many types of exercise devices, including elliptical devices, treadmills, stair steppers, stationary bicycles, ski simulators and the like, provide for motion of a user's arms during exercise. For example, the elliptical exercise devices shown in U.S. Pat. Nos. 5,242,343; 5,383,829; 5,577,985; 5,562,574 and 6,398,695 include members and linkages which allow a user's arms to move back and forth during exercise. Some other exercise devices which provide for arm motion are shown in U.S. Pat. Nos. 4,949,954; 2,603,486; 4,869,494; 5,653,662; 5,913,751; 5,993,359; 5,836,855; 5,788,610; 6,024,676; 6,017,295; 6,017,294; 5,957,814; 5,947,872; 5,916,064; 5,823,919 and 5,921,894.
While a number of exercise devices, and in particular certain elliptical exercise devices, provide a natural range of motion for a user's lower body muscles which simulates a natural running and stepping action, the present invention recognizes that the arm and shoulder motion provided by heretofore available exercise equipment does not simulate a natural upper body motion. Referring now to FIG. 1, there is shown a schematic depiction of a person participating in a machine-assisted exercise. As shown in FIG. 1, the person 10 is using an exercise device, which in this instance is represented by the block 12. It is to be understood that this block 12 is meant to represent any generic exercise device such as a treadmill, elliptical device, stair stepper, stationary cycle, ski simulator or the like. Arrow A traces the path of motion of a user's arm which is achieved through the use of conventional exercise equipment of the type referred to hereinabove. As will be noted, the user's hand travels along a path of motion, A, which is generally horizontal. This path of motion A causes the user's arm to pivot primarily at the elbow, and may also cause some small degree of pivoting at the shoulder joint. Analysis of this motion demonstrates that it is not equivalent to the arm motion which a person's body undergoes when he or she is participating in unassisted aerobic exercise such as running, jogging or walking at a brisk pace. In such instance, the person's hand traverses a path as shown by arrow B. This preferred path of travel is curved and generally inclined relative to the horizontal. It produces a hand and arm movement in which pivoting of the arm occurs primarily at the shoulder joint. An arm action of this type produces a more productive and beneficial aerobic workout and lessens the chance of muscle fatigue or joint trauma. As a consequence, exercise which incorporates this type of arm motion is generally more comfortable for the user, which assures better compliance with an exercise program.
As will be detailed hereinbelow, the present invention provides an arm motion assembly for an exercise device. The arm motion assembly of the present invention provides a very natural arm motion in which a user's arm pivots about the shoulder joint. The assembly of the present invention may be readily implemented in a variety of configurations and is readily adapted to various exercise devices.